On a recent muggy July morning I walked up through some heavily landscaped hedge screening, typical of an Edgartown Village property, to find another usual summer site on Martha’s Vineyard: homeowners lounging poolside by their brand new guesthouse. They were enjoying late morning coffees while their golden retriever Stella pounced around the new decking and perfectly sodded lawn. I introduced myself, “Rose from Sandpiper Realty ... I’m here to meet with Ben and Heather.”
The homeowner excitedly jumped up and welcomed me into her home like any other friend stopping by to admire the recently completed, totally polished two bedroom guest house, complete with massive second story deck, and framed by a full tennis court. We glided effortlessly from the outside in. Upon nearing the floating steps leading down to the lower level, she yelled out, “Rose is here, she’s wearing shoes!”
“No shoes!” I heard from another voice that bounced off the walls below.
Ben’s face popped up to see us from the foot of the stairs. “But they match her whole look,” the homeowner exclaimed. Ben sees my rubber-soled Toms wedges and concedes that since they are not “hard shoes” I can keep them on. He then invited me to the action center of the home today: the basement.
This negotiation is what building is all about: A builder and his client, a homeowner and her builder, discuss why certains things matter and why others don’t, to find a healthy balance from both perspectives. I was there to shadow Ben and his associate Heather as they did a third round of testing their building’s energy efficiency. This would also serve as Heather’s final “dry run” through this process, in preparation for her HERS Rating certification exam. Heather is a member of Ben’s building crew. She has already completed a course in green building practices, helped build this guest house, and by becoming a certified HERS Rater, she is closing the circle and strengthening the connection between building practices and energy ratings.
A certified HERS Rater conducts a series of tests on the house, including a blower door test and a duct test, to generate a score on the Home Energy Rating System Index. The lower the score, the more energy efficient the home.
From the blower door test set up in the basement, I watched these two speak their own language filled with measurements of pressure, volume and velocities, with frequent focus on vents, electrical outlets and other “exterior penetrations”. They both expressed a sense of thrill and suspense, in moving toward that final index number that would tell them how good of a job they did in building this structure. As Heather slowly cranked up the fan speed on the blower door test, the air hummed and a low whistle sounded upstairs in the living space. Ben made a quiet comment to me, so as not to distract Heather “It’s exciting to see how our building is going to perform.”
Once the fan was at 50 pascals, we walked upstairs and felt for gaps at the vents, windows, doors and everywhere where the envelope had been opened in the building process. This was just anecdotal evidence of course.
For what they called “the really boring part” we sat on the cork floored basement, surrounded by insulation that was once some kind of steel product (Roxul, recycled slag) as they read numbers out loud to each other, and made calculations. The test result came out at 1.0 ACH (the air exchange rate “air changes per hour”). This is seven times better than the building code from which the house was permitted, three times better than current building code and slightly above Passive House Standards.
In my follow up with Ben he commented,
“It’s good! It is TIGHT and TIGHT is a good thing. The benefits are improved indoor air quality, increased comfort; a tight house is less likely to have rot or mold occur in the building assembly due to interior humidity gains and finally it has less expensive heating cooling bills compared to a similar house.”
Since the house is so tight, measuring in at under 3 ACH (air changes per hour) it actually requires mechanical ventilation.
What to do with a HERS Rating
As the general contractor, Ben is using the HERS Rating to check his own work. A homeowner can get a HERS Rating at any point in the lifetime of a home and will get a detailed report that provides suitable retrofit recommendations and specifications that will rectify the home’s energy problems. In a bigger scope this will increase the comfort level in the home, making the house less drafty, and better control utility costs. On the West Coast, where HERS Ratings have been established as benchmarks for measuring energy efficiency, those homes which are rated as energy efficient seem to sell faster, and fetch higher prices. This is an added benefit for homeowners thinking of selling their home.
Green Building is centered on a commitment to quality. I’ve asked Ben, who owns Building Shelter, Inc. to help me explain to my own clients what green building means, and he boils it down perfectly as “building above code.” The building codes we are working with today will change and become more stringent and focused on resource and energy sustainability. Making choices to build to the current green standards helps position a house to be more in line with future code and well ahead of the curve.